JP3466045B2 - Non-aqueous electrolyte secondary battery - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-aqueous electrolyte secondary battery using a lithium ion conductive non-aqueous electrolyte as a negative electrode and a positive electrode active material capable of occluding and releasing lithium, and in particular, The present invention relates to a secondary battery having high voltage, high energy density, excellent charge / discharge characteristics, long cycle life, high reliability, and a novel battery structure.

[0002]

Non-aqueous electrolyte batteries using lithium as a negative electrode active material have advantages of high voltage, high energy density, small self-discharge and excellent long-term reliability. It has already been widely used as a power source for industrial use. However, with the remarkable development of portable electronic devices and communication devices in recent years,
A wide variety of devices that require a large current output for batteries as power sources have appeared, and rechargeable / dischargeable secondary batteries with high energy density have been strongly demanded from the viewpoint of economy and reduction in size and weight of devices. ing. Therefore, research and development for promoting the non-aqueous electrolyte battery having a high energy density into a secondary battery have been actively carried out and partially put into practical use, but energy density, charge / discharge cycle life, reliability, etc. are still unsatisfactory. It is enough.

Conventionally, as the positive electrode active material constituting the positive electrode of this type of secondary battery, depending on the form of charge / discharge reaction, the following 3
Some types of species have been found. The first type is a metal chalcogenide such as TiS ₂ , MoS ₂ , NbSe ₃ or MnO ₂ , MoO ₃ , V ₂ O ₅ , Li _X CoO ₂ , L.
Like metal oxides such as i _x NiO ₂ and Li _x Mn ₂ O _4, only lithium ions (cations) are involved in intercalation and deintercalation reactions between crystal layers, lattice positions or lattice gaps. Type that goes in and out. Second
Type is a type such as polyaniline, polypyrrole, polyparaphenylene, etc., in which only anions are stably doped and dedoped due to conductive polymers such as conductive polymers. The third type is a type (intercalation, deintercalation or doping, dedoping, etc.) in which both lithium cations and anions can enter and exit, such as graphite intercalation compounds and conductive polymers such as polyacene. .

On the other hand, as the negative electrode active material constituting the negative electrode of this type of battery, when metal lithium is used alone, the electrode potential is the most base, so that the positive electrode using the positive electrode active material as described above is used. The combined battery has the highest output voltage and high energy density, which is preferable, but there was a problem that dendrites and passivation compounds were formed on the negative electrode during charging and discharging, and deterioration due to charging and discharging was large and cycle life was short. . In order to solve this problem, as a negative electrode active material, (1) lithium and Al, Zn, Sn, Pb, Bi, Cd
Alloys with other metals such as (2) WO ₂ , MoO ₂ , Fe
An intercalation compound or insertion compound in which lithium ions are occluded in the crystal structure of an inorganic compound such as ₂ O ₃ or TiS ₂ , graphite, or a carbonaceous material obtained by firing an organic substance, and (3) lithium ion-doped polyacene It has been proposed to use a substance capable of inserting and extracting lithium ions, such as a conductive polymer such as or polyacetylene.

Generally, a battery is constructed by combining a negative electrode using a substance capable of inserting and extracting lithium ions other than metallic lithium as described above as a negative electrode active material, and a positive electrode using the positive electrode active material as described above. In this case, since the electrode potential of these negative electrode active materials is nobler than the electrode potential of metallic lithium, there is a drawback that the operating voltage of the battery is considerably lower than that when metallic lithium is used alone as the negative electrode active material. For example, lithium and Al, Zn, Pb, Sn, B
When using alloys such as i and Cd, 0.2 to 0.8 V,
For carbon-lithium intercalation compounds, 0 to 1V, MoO ₂ and W
0.5 to 1.5 for lithium ion insertion compounds such as O ₂
The V operating voltage drops. In addition, since elements other than lithium also serve as negative electrode constituent elements, the capacity and energy density per volume and weight are significantly reduced.

Furthermore, when the alloy of (1) above with lithium and another metal is used, the utilization efficiency of lithium during charge / discharge is low, and cracks occur in the electrode due to repeated charge / discharge, resulting in cracking. However, in the case of the lithium intercalation compound or the intercalation compound of (2), there is a deterioration of the crystal structure or the generation of irreversible substances due to overcharging and discharging, and the electrode potential. Since there are many high (noble) batteries, there is a drawback that the output voltage of the battery using this is low. In the case of the conductive polymer of (3),
There is a problem that the charge / discharge capacity, especially the charge / discharge capacity per volume is small. Further, a conventional lithium secondary battery uses a separator made of a fine porous insulating film made of a synthetic resin such as a woven cloth, a nonwoven cloth, and a porous polypropylene film, and has a positive electrode layer on one side of these separators and the other side. A battery configuration having a negative electrode layer has been known. The separator holds the electrolytic solution and allows lithium ions to be electrodeposited through the pores on the negative electrode, thereby enabling a battery reaction between the positive and negative electrodes. However, in a lithium secondary battery using a separator made of a conventional porous insulating film, the charge / discharge capacity gradually decreases as the charge / discharge is repeated, and the cycle life of the battery, or the maintainability of the charge / discharge capacity is reduced. There are problems such as poorness and inferior heat resistance of the synthetic resin microporous film.

[0007]

Therefore, in the present invention, in order to obtain a secondary battery having a high voltage, a high energy density, excellent charge / discharge characteristics, and a long cycle life, the electrode potential with respect to lithium is determined. Is low (basic), there is no deterioration such as crystal structure collapse or irreversible substance generation due to storage and release of lithium ions during charge and discharge, and the amount of lithium ions that can be stored and released reversibly, that is, the effective charge and discharge capacity Larger negative electrode active materials are needed.

On the other hand, of the above-mentioned positive electrode active materials, the first type generally has a large energy density, but has a drawback that if it is overcharged or overdischarged, it is greatly deteriorated due to crystal collapse or generation of irreversible substances. . On the contrary, the second and third types have a drawback that the charge / discharge capacity, especially the charge / discharge capacity per volume and the energy density are small. Therefore, in order to obtain a secondary battery having excellent overcharge characteristics and overdischarge characteristics, high capacity, and high energy density, there is no crystal collapse or irreversible substance generation due to overcharge overdischarge, and reversible There is a need for a positive electrode active material that can store and release lithium ions in a larger amount.

Further, in the separator, there is a need for a separator which is excellent in ion permeability, has high strength, is thin and has excellent insulating properties, and is also excellent in heat resistance.

[0010]

In order to solve the above problems, the present invention provides a negative electrode active material for a battery of this type,
A negative electrode comprising a lithium-containing silicon oxide or silicate, electronically conductive powdery carbon and a resin binder, a positive electrode using a metal oxide containing a transition metal as a constituent element as an active material, and glass It proposes to use a separator using a fiber material.

The negative electrode active material contains lithium in the crystal structure or amorphous structure of a silicon oxide or silicate containing lithium, and absorbs and absorbs lithium ions by an electrochemical reaction in a non-aqueous electrolyte. A releasable lithium-silicon composite oxide is used. The state of lithium in this composite oxide is preferably mainly ionic, but is not necessarily limited.

The lower oxide Li _x SiO _{y of} silicon containing lithium used as the negative electrode active material of the battery of the present invention.
(However, x ≧ 0, 2>y> 0), the following two types of methods are preferable, but not limited thereto. The first method is to synthesize a lower silicon oxide SiO _y (where 2>y> 0) not containing lithium in advance, and obtain the obtained lower silicon oxide SiO _y and lithium or a substance containing lithium. Is a method of causing lithium ions to be absorbed in the lower oxide SiO _y of silicon to obtain a lower oxide Li _x SiO _y of silicon containing lithium. Examples of such a lower oxide SiO _y of silicon include SiO _1.5 (Si ₂ O ₃ ), S
iO _1.33 (Si ₃ O ₄ ), SiO and SiO _0.5 (Si
Other than stoichiometric composition such as ₂ O), y may be of any composition in which y is greater than 0 and less than 2. Further, these lower oxides of silicon such as SiO _y can be produced by various known methods as described below. That is, (1) a method in which silicon dioxide SiO ₂ and silicon Si are mixed at a predetermined molar ratio and heated in a non-oxidizing atmosphere or in a vacuum, (2) silicon dioxide SiO ₂ is a reducing gas such as hydrogen H _2. A method of heating in a predetermined amount to reduce a predetermined amount, (3) a method of mixing silicon dioxide SiO ₂ with a predetermined amount of carbon C or a metal, and heating to reduce a predetermined amount, (4) an oxygen gas or oxidation of silicon Si A method of heating an object to oxidize it by a predetermined amount, (5) a CVD method or a plasma CVD method in which a mixed gas of a silicon compound gas such as silane SiH ₄ and oxygen O ₂ is heated or plasma-decomposed.

On the other hand, as the substance containing lithium for use in the electrochemical reaction, for example, lithium ions such as those used for the positive electrode active material or the negative electrode active material mentioned in the above [Prior Art] are mentioned. An active material capable of occluding and releasing can be used. The absorption of lithium ions by the electrochemical reaction of the silicon to the lower oxide SiO _y can be performed in the battery after the battery is assembled, or in the battery or outside the battery during the battery manufacturing process. Can be done as follows. That is, (1) one of the electrodes (working electrode) is formed by molding the lower oxide of silicon or a mixture of the lower oxide of silicon and a conductive agent, a binder or the like into a predetermined shape, and contains metallic lithium or lithium. The other electrode (counter electrode) is used as the other electrode (counter electrode) to come into contact with the lithium ion conductive non-aqueous electrolyte so that both electrodes face each other to form an electrochemical cell, and the working electrode is energized with an appropriate current in the direction of cathodic reaction. Lithium ions are chemically absorbed in the lower oxide of silicon. A non-aqueous electrolyte secondary battery is constructed by using the obtained working electrode as it is as a negative electrode or as a negative electrode active material constituting the negative electrode. (2) The low-grade oxide of silicon or a mixture of the low-grade oxide of silicon and a conductive agent, a binder or the like is molded into a predetermined shape, and lithium or a lithium alloy or the like is pressure-bonded or brought into contact with the laminated electrode. The obtained product is incorporated into a non-aqueous electrolyte secondary battery as a negative electrode. By forming a kind of local battery by touching the electrolyte with this laminated electrode in the battery,
A method of self-discharging and electrochemically occluding lithium in the lower oxide of silicon. (3) A non-aqueous electrolyte secondary battery is constructed using the lower oxide of silicon as a negative electrode active material and a material containing lithium and capable of inserting and extracting lithium ions as a positive electrode active material. A method in which lithium ions released from the positive electrode by being charged when used as a battery are occluded in the lower oxide of silicon.

The second method is a method of synthesizing each of lithium and silicon as a simple substance or a compound thereof at a predetermined molar ratio and heating the mixture in a non-oxidizing atmosphere or an oxygen-controlled atmosphere. . The respective compounds of lithium and silicon, which are the starting materials, are heated in a non-oxidizing atmosphere such as oxides, hydroxides, salts such as carbonates and nitrates, or organic compounds to form oxides. Compound is good. In particular, the lower oxide SiO _y of silicon shown in the above first method is used as a compound of silicon, and these are mixed with lithium or a compound having oxygen of lithium, and heated in an inert atmosphere or in a vacuum. The method is preferable because it is easy to control, easy to manufacture, and excellent in charge / discharge characteristics.

Further, these starting materials may be water or alcohol,
It is also possible to dissolve or disperse in a solvent such as glycerin, uniformly mix and / or react in the solution, then dry and perform the above heat treatment. In particular, it depends on the method of adding the predetermined amount of silicon or the above-mentioned lower oxide of silicon or a dispersion or aqueous solution thereof to an aqueous solution of lithium hydroxide and mixing them, drying and dehydrating the reacted product, and then performing the heat treatment described above. For example, a more uniform product can be obtained by heat treatment at a lower temperature.

Although the heating temperature varies depending on the starting material and the heating atmosphere, it is usually possible to synthesize it at 400 ° C or higher, while at temperatures of 800 ° C or higher, it is disproportionated to silicon Si and silicon dioxide SiO ₂ . 400 because it may react
A temperature of ~ 800 ° C is preferred. Further, when various silicic acids having hydrogen as a compound of silicon are used as a starting material, or when lithium hydroxide or the like is used as a lithium compound, hydrogen is not completely desorbed by heat treatment, and It is possible that a part of them remains in the product and lithium and hydrogen coexist, which is included in the present invention. Further, together with lithium or a compound thereof and silicon or a compound thereof, a small amount of another alkali metal such as sodium, potassium or rubidium, an alkaline earth metal such as magnesium or calcium and / or iron, nickel, manganese, vanadium, titanium or lead. , Aluminium, germanium, boron, phosphorus and other metals or non-metal elements such as simple substances or compounds thereof are also mixed and heat-treated to remove a small amount of these metals or non-metals other than lithium from lithium and It can be made to coexist with silicon, and these cases are also included in the present invention.

The lithium-containing silicon lower oxide thus obtained can be used as a negative electrode active material as it is or after being subjected to processing such as pulverizing and granulating, if necessary, In the same manner as in the first method, the lithium-containing silicon lower oxide is converted to the lithium-containing silicon lower oxide by an electrochemical reaction between the lithium-containing silicon lower oxide and lithium or a lithium-containing substance. Further, a material in which the amount of lithium is increased or decreased by occluding lithium ions or conversely releasing lithium ions from the lower oxide of silicon containing lithium may be used as the negative electrode active material.

The lithium-containing low-grade silicon oxide Li _x SiO _y thus obtained is used as the negative electrode active material. On the other hand, as the positive electrode active material, as described above, Li _x Mn
By using a metal oxide such as O _y , lithium ions and / or anions can be occluded and released. The lithium-containing silicon oxide of the present invention, particularly the lower oxide Li _x
The negative electrode using SiO _y as the negative electrode active material has the advantages that the electrode potential with respect to metallic lithium is low (base) and the charge / discharge capacity in a base region of 1 V or less is significantly large. By combining with a positive electrode using an (noble) active material having an electrode potential of 2 V or higher, there is an advantage that a secondary battery having higher voltage and higher energy density and excellent charge and discharge characteristics can be obtained. . In particular, a composite oxide having a layered structure containing lithium and having a composition formula of Li _x MnO _y together with a negative electrode using a negative electrode active material composed of a lithium-containing silicon oxide or a silicate according to the present invention. When used in combination with a positive electrode that uses a positive electrode active material composed of a material, a secondary battery having a long cycle life with a high energy density, excellent charge / discharge characteristics, and little deterioration due to overcharge / overdischarge can be obtained. Therefore, it is particularly preferable.

The composite oxide Li _x MnO _{y of} manganese Mn and lithium used as the positive electrode active material of the battery of the present invention.
The following two types of methods are preferable as the production method, but the method is not limited to these.

The first method is to mix the above-mentioned manganese Mn, the respective metal elements and lithium Li or their compounds in a predetermined molar ratio, and control the amount of oxygen in an inert atmosphere or in a vacuum or in a vacuum. This is a method of synthesizing by heating in an atmosphere. Manganese Mn and lithium L as starting materials
As the respective compounds of i, compounds such as respective oxides, hydroxides, salts such as carbonates and nitrates, organic compounds and the like which generate oxides by heating in an inert atmosphere or in a vacuum are preferable. Although the heating temperature varies depending on the starting material and the heating atmosphere, the synthesis is usually possible at 400 ° C. or higher, preferably 600 ° C. or higher, more preferably 700 ° C.

The composite oxide of manganese Mn and lithium Li thus obtained can be used as the active material of the positive electrode as it is or after being subjected to processing such as pulverizing and granulating if necessary. In addition, as in the second method described below, further lithium is added to the composite oxide by an electrochemical reaction between the lithium Li-containing composite oxide and metallic lithium Li or a substance containing lithium. It is possible to use as the active material, the lithium content is increased or decreased by occluding the ions or, conversely, releasing the lithium ions from the composite oxide.

The second method is to cause the composite oxide MnO _y to occlude lithium ions by an electrochemical reaction between the above-mentioned manganese, the composite oxide MnO _y, and lithium or a substance containing lithium to form a mixture of manganese and lithium. It is a method of obtaining the composite oxide. As the substance containing lithium for use in this electrochemical reaction, for example, a substance capable of inserting and extracting lithium ions such as those used for the positive electrode active material mentioned in the above-mentioned conventional section can be used.

Such a manganese composite oxide MnO _y
The absorption of lithium ions by an electrochemical reaction can be performed inside the battery after the battery is assembled, or inside or outside the battery during the battery manufacturing process. Specifically, it is performed as follows. You can That is, (1) one electrode (working electrode) is formed by molding a mixture of manganese and a complex oxide MnO _y or a mixture thereof with a conductive agent and a binder into a predetermined shape, and contains metallic lithium or lithium. The substance to be used is the other electrode (counter electrode), which is in contact with a lithium ion conductive non-aqueous electrolyte so that both electrodes face each other to form an electrochemical cell, and the working electrode is energized with an appropriate current in the direction of cathodic reaction or A method of discharging and electrochemically occluding lithium ions in the composite oxide. A non-aqueous electrolyte secondary battery is constructed by using the obtained working electrode as it is as an active material. (2) A composite oxide of manganese and MnO _y or a mixture of them and a conductive agent, a binder, etc., is molded into a predetermined shape, and lithium or an alloy of lithium is pressure-bonded or contacted thereto and laminated. Is incorporated into a non-aqueous electrolyte secondary battery as an electrode. A method of forming a kind of local battery by contacting the laminated electrode with an electrolyte in the battery and self-discharging to electrochemically occlude lithium in the composite oxide.
(3) A non-aqueous electrolyte secondary battery is constituted by using a manganese composite oxide MnO _y as an active material of one electrode and using lithium in the other electrode as a substance capable of inserting and extracting lithium ions. A method in which lithium ions are occluded in the composite oxide by charging or discharging when used as a battery.

The composite oxide Li _x MnO _y of manganese Mn and lithium Li thus obtained is used as the active material of the positive electrode. On the other hand, as the separator of the present invention, as described in the above [Problems to be solved by the invention], the ion permeability is excellent, the strength is high, the thickness is thin and the insulation is excellent, and the heat resistance is also excellent. As a separator, the weight is 70 g / m ² , the thickness is 0.21 mm, and the air permeability is 17 se.
c, glass fiber having a tensile strength of 500 g / 15 mm width (or more) and a heating loss of 10% is used.

The battery of the present invention comprises the above-mentioned negative electrode, positive electrode and separator. Thus obtained, when using the electrolyte solution in combination with the negative electrode and the positive electrode and the separator of the present invention, the charge and discharge characteristics are excellent especially at high energy density, and the deterioration due to overcharge overdischarge is small and the cycle life is long. It is particularly preferable because a long secondary battery can be obtained.

As the electrolyte, γ-butyrolactone, pr
Ropylene carbonate, ethylene carbonate, butyre
Carbonate, dimethyl carbonate, diethyl car
Bonate, methyl formate, 1,2-dimethoxy ether
Tan, tetrahydrofuran, dioxolane, dimethyl fluoride
Supported by organic solvents such as ormamide alone or in a mixed solvent.
LiClO as a solution_Four, LiPF₆, LiBF_Four, Li
CF₃SO₃Non-aqueous solution of lithium ion dissociable salt
(Organic) electrolytes, polyethylene oxide and polyphosph
The lithium salt was solid-dissolved in a polymer such as a cross-linked benzene.
Polymer solid electrolyte or Li₃Inorganic solid such as N and LiI
Lithium ion conductive non-aqueous electrolyte such as body electrolyte
Non-aqueous electrolysis containing ethylene carbonate (EC)
A liquid can be used. Since EC has a high freezing point,
Desirable to be 80% or less by volume ratio to the total solvent for dissolution.
Good Also, since EC is a highly viscous solvent,
Formula 1 is used to increase conductivity and stabilize
R ・ R 'type alkyl carbonate (including R = R')
It is desirable to contain R and R'are C_nH_{2n + 1}so
In case of n = 1, 2, 3, 4, 5 in the alkyl group shown
Especially, it is preferable because it has high ionic conductivity and low viscosity. During ~
However, in the formula 1, R and R ′ are methyl groups (n = 1) and ethyl groups.
Group (n = 2), dimethyl carbonate (DM
C), diethyl carbonate (DEC) and methyl ethyl
Carbonate and the like are more preferable. Furthermore, with EC and formula 1
The R · R ′ type alkyl carbonate represented by
It is desirable to form a solvent, and EC and R / R 'type alkyl
When the mixing ratio of carbonate is about 1: 1 by volume,
Since the maximum conductivity is achieved, the mixing ratio is about 3: 1 by volume.
The ratio of 1: 3 is particularly preferable. Also, support in electrolyte
As described above, the electrolyte has Li + ions in the solvent.
It is a salt that dissociates with
It is good if there is, for example, LiClO_Four, LiPF₆, LiB
F_Four, LiCF₃SO ₃, Li (CF₃SO₂)₂N is good
Yes.

FIG. 1 is a sectional view showing an example of a test cell used for evaluating the charge / discharge characteristics of the active material of the non-aqueous electrolyte secondary battery according to the present invention. In the figure, reference numeral 1 denotes a negative electrode case which also serves as a negative electrode terminal, which is obtained by drawing a stainless steel plate having Ni plated on one outer surface. Reference numeral 3 is a negative electrode pellet, a lithium foil having a predetermined thickness is punched out in a circular shape onto the negative electrode pellet, and the negative electrode pellet 2 is pressed, and 2 is a working electrode current collector made of a conductive adhesive containing carbon. The case 1 was adhered and electrically connected, and these were used as a negative electrode unit. Reference numeral 7 denotes a positive electrode case made of stainless steel having one outer surface plated with Ni, which also serves as a positive electrode terminal. Reference numeral 5 is a positive electrode pellet, 6 is a working electrode current collector made of a conductive adhesive containing carbon, and the positive electrode 5 and the positive electrode case 7 are bonded and electrically connected to each other to form a positive electrode unit. . 4 is a separator made of glass fiber material, which is impregnated with the electrolytic solution 9. Reference numeral 8 is a gasket mainly made of polypropylene, which is interposed between the negative electrode case 1 and the positive electrode case 7 to maintain the electrical insulation between the negative electrode and the positive electrode, and at the same time, the opening edge of the positive electrode case is bent inward. The battery contents are thus hermetically sealed. The electrolyte used was one in which 1 mol / l of lithium hexafluorophosphate LiPF ₆ was dissolved in a mixed solvent of ethylene carbonate and ethyl methyl carbonate in a volume ratio of 1: 1.

[0028]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention is directed to a negative electrode comprising a lithium-containing silicon oxide or silicate, electronically conductive powdery carbon, and a resin binder, and a metal containing a transition metal as a constituent element. It proposes to use a positive electrode using an oxide as an active material and glass fiber as a separator.

<Anode> For the anode used in the lithium secondary battery of the present invention, lithium or a substance capable of inserting and extracting lithium is used. Examples thereof include lithium metal, lithium / silicon, lithium / silicon oxide, and carbon-based materials that electrochemically absorb and release lithium ions.

As the negative electrode active material, lithium, a lithium alloy, or a carbon material capable of inserting and extracting lithium ions is used. Among these battery systems, when lithium or a lithium alloy is used as the negative electrode active material, by repeating the cycle number, the dissolution and precipitation reaction of lithium is repeated, and acicular dendrite lithium is formed in due course. There are problems such as short circuit due to penetration of the diaphragm, capacity deterioration due to separation from the current collector, capacity deterioration due to reaction with the electrolytic solution, and the like. Therefore, for the purpose of fundamentally eliminating the formation of these dendrites, studies have been made on the use of a carbon material capable of inserting and extracting lithium ions as a negative electrode active material, and some have been put to practical use.

As the silicon powder constituting the negative electrode, those produced by crushing or the like can be used. In addition, silicon that is reduced in the battery after battery assembly, or in the battery during the battery manufacturing process or outside the battery by an electrochemical reaction between an oxide of silicon and lithium or a substance containing lithium is used. That is also an effective means. As the negative electrode raw material, a mixture of silicon and silicon oxide may be used.

Various compounds may be included in the silicon powder of the present invention. For example, transition metal (4th in the periodic table,
Group III-A to Group II elements of the 5th and 6th periods
-Elements belonging to Group B) or elements of Group IV-B of the periodic table,
Alkali metals (elements I-A and II-A of the periodic table)
Alternatively, P, Cl, Br, I, F may be included to obtain a silicon alloy powder. The amount of compound added is 0 to 20 mol%
Is preferred.

When silicon is used, the equivalent of lithium insertion in the negative electrode is preferably 2 to 4.5 equivalents. When SiO is used, it is preferably 2.5 to 6.5 equivalents. Examples of the substance for doping lithium into the silicon or the oxide of silicon of the present invention include lithium metal, lithium alloy and the like, and calcined carbonaceous compounds capable of inserting and extracting lithium ion or lithium metal. The purpose of combined use of the above lithium metal and lithium alloy is
It is for reducing the oxide of silicon and for doping lithium without adding lithium in the battery.

<Positive electrode> Specific examples of the positive electrode material include inorganic compounds such as transition metal oxides containing alkali metals and transition metal chalcogens (iron sulfide, titanium disulfide, molybdenum disulfide, etc.), polyacetylene, polyparaphenylene,
Examples of the positive electrode used in ordinary secondary batteries include conjugated polymers such as polyphenylene vinylene, polyaniline, polypyrrole, and polythiophene, crosslinked polymers having a disulfide bond, and thionyl chloride.
Among these, in the case of a secondary battery using a non-aqueous electrolyte containing a lithium salt, cobalt, manganese, molybdenum,
Transition metal oxides and transition metal chalcogens such as vanadium, chromium, iron, copper and titanium are preferably used. Li
CoO ₂ and LiNiO ₂ are most preferably used because they have a high voltage and a large energy density.

The positive electrode active material used in the present invention may be a transition metal oxide capable of reversibly inserting and releasing lithium ions, but a lithium-containing transition metal oxide is particularly preferable.
Preferred lithium-containing transition metal oxide positive electrode active materials used in the present invention include oxides containing lithium-containing Mn. Alkali metals other than lithium (elements IA and IIA of the periodic table), and / or Al, G
a, In, Ge, Sn, Pb, Sb, Bi, Si, P,
You may mix B etc. Mixing amount is 0 for transition metal
-30 mol% is preferable. More preferred lithium-containing transition metal oxide positive electrode active material used in the present invention,
Lithium compound / transition metal compound (transition metal here means Ti, V, Cr, Mn, Fe, Co, Ni, Mo,
The total molar ratio of at least one selected from W is 0.
It is preferable to mix them so as to be 2 to 3.0 and synthesize them. As a particularly preferable lithium-containing transition metal oxide positive electrode active material used in the present invention, a lithium compound / transition metal compound (wherein the transition metal is V, Cr, Mn, F
It is preferable to mix and synthesize so that the total molar ratio of at least one selected from e, Co, and Ni) is 0.2 to 3.0. Particularly preferable lithium-containing transition metal oxide positive electrode active material used in the present invention is Li _x MnO _y.
(Here, mainly a transition metal containing Mn), x = 0.
2 to 1.2 and y = 1.4 to 3) are preferable.
Here, the above-mentioned x value is a value before the start of charge / discharge, and increases / decreases due to charge / discharge.

The positive electrode active material of the present invention may contain one or more transition metal elements, typical elements, and rare earth elements, and may be formed as a composite metal oxide or a mixture. Particularly preferred dopants are P, Co, Ni, Ti, V, Zr, Nb, M
o, W, Fe, Cr and the like. The average particle size of the positive electrode active material used in the present invention is preferably 500 μm or less,
More preferably 100 μm or less, especially 50 to 0.1 μm
Is good. The form of the active material is preferably a primary particle aggregate having an average particle size of 1 micron or more and 20 microns or less, which is an aggregate of primary particles having an average particle size of 0.1 micron or more and 2.5 microns or less, and particularly preferably. , Average particle size 0.1
It is preferably composed of primary particle aggregates having an average particle size of 3.5 micron or more and 9.5 micron or less, which is an aggregate of primary particles of micron or more and 2.5 micron or less. Further, in the above-mentioned primary particle aggregate, 80% or more of the total volume preferably has a particle size of 1 micron or more and 15 microns or less, more preferably 85% or more of the total volume, and further preferably 90% or more of the total volume. is there. Specific surface area is 0.05-100
m ² / g, more preferably 0.1 to 50 m ² /
g, particularly 0.1 to 30 m ² / g is preferable.

The positive electrode active material of the present invention can be used as a mixture of two or more kinds. It can be applied when changing the voltage range to be used or detecting the remaining capacity by voltage. <Electrode shape / formation method> The electrode shape can take various shapes such as a plate shape, a film shape, a column shape, or a shape formed on a metal foil depending on the intended battery. The method of integrating the carbon fiber and the electrode plate is not particularly limited, but, for example, first, the carbon fiber is formed into a sheet by aligning the carbon fibers in a uniaxial direction, and the sheet is formed into a sheet by roll pressing or the like. There is a method of pressure-bonding to a metal foil, and a method of adhering sheet-like carbon fiber to a metal foil using a binder.

<Separator> A conventional separator is a porous material having continuous ventilation holes that is durable to an electrolytic solution or an electrode active material and has no electronic conductivity, and is a cloth or non-woven fabric made of polyethylene or polypropylene. Alternatively, a porous insulating film is used. The pore size of the separator is generally used for batteries.

The separator used in the present invention is woven cloth, non-woven cloth or porous glass fiber and has a weight of 60.
-80g / m ² , thickness 0.10-0.30mm, air permeability 10-25sec, tensile strength 400g or more / 15mm
A material having a width and a weight loss on heating of 5 to 15% is preferable. The separator is fixed in the battery case so that there is no practical problem.

<Conductive Agent> A conductive agent, a binder, a filler or the like can be added to the electrode mixture. The type of the conductive agent is not particularly limited and may be a metal powder, but a carbon-based one is particularly preferable. The most common carbon materials are natural graphite (scaly graphite, flake graphite, earth graphite, etc.), artificial graphite, carbon black, channel black, thermal black, furnace black, acetylene black,
Ketjen black, carbon fiber, etc. are used. Further, as the metal, metal powder such as copper, nickel, silver or the like, or metal fiber is used. Conducting polymers are also used. The mixing ratio varies depending on the electric conductivity of the active material, the shape of the electrode, etc., but it is appropriate to add 2 to 40% to the active material.

<Binder> The binder is preferably insoluble in the electrolytic solution, but is not particularly limited. Usually, polyacrylic acid and polyacrylic acid neutralized product, polyvinyl alcohol, carboxymethyl cellulose, starch, hydroxypropyl cellulose, regenerated cellulose, diacetyl cellulose, polyvinyl chloride, polyvinyl pyrrolidone, tetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, ethylene. -Propylene-diene terpolymer (EPDM), sulfonated E
Polysaccharides such as PDM, styrene-butadiene rubber, polybutadiene, fluororubber, polyethylene oxide, polyimide, epoxy resin, phenol resin, thermoplastic resin,
Thermosetting resins, polymers having rubber elasticity, etc. are used alone or as a mixture thereof. The amount of the binder added is not particularly limited, but is preferably 1 to 50% by weight. In particular, when used for an active material having a large lithium occlusion amount, a large amount of 5 to 40% by weight is preferable because it causes a structural change and a volume change due to charge and discharge.

<Filler> As the filler, any fibrous material can be used as long as it does not cause a chemical change in the constructed battery. Generally, olefin polymers such as polypropylene and polyethylene, fibers such as glass and carbon are used. The amount of the filler added is not particularly limited, but is preferably 0 to 30% by weight.

<Electrolytic Solution> The electrolytic solution is not particularly limited, and an organic solvent used in conventional non-aqueous secondary batteries is used. As the organic solvent, cyclic esters, chain esters, cyclic ethers, chain ethers, etc. are used, and specifically, propylene carbonate (PC), ethylene carbonate (EC), butylene carbonate (BC). , Vinylene carbonate, dimethyl carbonate (DMC), diethyl carbonate (DEC), γ-
Butyrolactone (γBL), 2-methyl-γ-butyrolactone, acetyl-γ-butyrolactone, γ-valerolactone, 1,2-dimethoxyethane (DME), 1,2-
Ethoxyethane, diethyl ether, ethylene glycol dialkyl ether, diethylene glycol dialkyl ether, triethylene glycol dialkyl ether, tetraethylene glycol dialkyl ether, dipropyl carbonate, methyl ethyl carbonate, methyl butyl carbonate, methyl propyl carbonate, ethyl butyl carbonate, ethyl propyl carbonate , Butyl propyl carbonate, propionic acid alkyl ester, malonic acid dialkyl ester, acetic acid alkyl ester, tetrahydrofuran (THF), alkyl tetrahydrofuran, dialkylalkyltetrahydrofuran, alkoxytetrahydrofuran, dialkoxytetrahydrofuran, 1,3-dioxolane, alkyl-1,3- Geo SORUN, 1,4-dioxolane,
2-methyltetrahydrofuran, dimethylsulfoxide, 1,3-dioxolane, formamide, dimethylformamide, dioxolane, acetonitrile, nitromethane, methyl formate, methyl acetate, methyl propionate,
Organic solvents such as ethyl propionate and phosphoric acid triester, and derivatives and mixtures thereof are preferably used.

From the viewpoint of suppressing the reductive decomposition reaction of the solvent, the use of an electrolytic solution in which carbon dioxide gas (CO ₂ ) is dissolved is effective in improving the capacity and the cycle life. Main impurities present in the mixed solvent (non-aqueous solvent) include water and organic peroxides (eg glycols, alcohols, carboxylic acids) and the like. It is considered that each of the impurities forms an insulating film on the surface of the graphitized product and increases the interfacial resistance of the electrode. Therefore, the cycle life and the capacity may be reduced. High temperature (6
(0 ° C or higher) Self-discharge during storage may increase. Therefore, it is preferable that the impurities are reduced as much as possible in the electrolytic solution containing the non-aqueous solvent. Specifically, the water content is 50 ppm or less and the organic peroxide content is 100 ppm.
It is preferably 0 ppm or less <solid electrolyte> In addition to the electrolytic solution, the following solid electrolytes can be used. Solid electrolytes are classified into inorganic solid electrolytes and organic solid electrolytes. Li-nitrides, halides, oxyacid salts, and the like are well known as inorganic solid electrolytes. For the organic solid electrolyte, a polyethylene oxide derivative or a polymer containing the derivative, a polypropylene oxide derivative or a polymer containing the derivative, a phosphoric acid ester polymer and the like are effective. A method of using an inorganic and organic solid electrolyte in combination is also known.

<Conductive salt> As an electrolyte contained in the electrolytic solution, an alkali metal, particularly lithium halide, perchlorate, thiocyanate, borofluoride, phosphorofluoride,
Arsenic fluoride, aluminum fluoride, trifluoromethyl sulfate, etc. are preferably used. Lithium perchlorate (LiClO ₄ ), lithium hexafluorophosphate (LiPF ₆ ), lithium borofluoride (LiB) are used as the supporting salt.
F ₄ ), lithium hexafluoroarsenide (LiAsF ₆ ), lithium trifluorometasulfonate (LiCF ₃ SO ₃ ), lithium bistrifluoromethylsulfonylimide [Li
One or more salts such as a lithium salt (electrolyte) such as N (CF ₃ SO ₂ ) ₂ ] can be used. The amount dissolved in the non-aqueous solvent is preferably 0.5 to 3.0 mol / 1.

Particularly, those containing EC, DEC and LiClO ₄ have a small bulge during storage at high temperature, and have no γ-BL, E
Those containing C, DME and LiClO ₄ had small internal resistance and good cycle characteristics. EC, EMC to Li
PF ₆ added, PC, EC, DME Li
The sample to which ClO ₄ was added also had a small internal resistance and good cycle characteristics.

<Electrolyte Additive> Additives may be added for the purpose of improving discharge and charge / discharge characteristics. Although it may be added directly to the active material, the most common method is to add it to the electrolytic solution. For example, toluene, pyridine (JP-A-4
9-108,525), triethylphosphite (JP-A-47-4,376), triethanolamine (JP-A-52-72,425), cyclic ether (JP-A-57-57).
152, 684), ethylenediamine (JP-A-58-8)
7,777), n-glyme (JP-A-58-87,77).
8), hexaphosphoric acid triamide (JP-A-58-87,7)
79), nitrobenzene derivatives (JP-A-58-214,
281), sulfur (JP 59-8,280), quinone imine dye (JP 59-68,184), N-substituted oxazolidinone and N, N'-substituted imidazolidinone (JP 59-154, 778), ethylene glycol dialkyl ether (JP-A-59-205,167), quaternary ammonium salt (JP-A-60-30,065), polyethylene glycol (JP-A-60-41,773), Pillow
Monomer (JP-A-60-79,677), 2-methoxyethanol (JP-A-60-89,075), AlCl3 (JP-A-61-88,466), conductive polymer-monomer of electrode active material. -(JP-A-61-161,673), triethylenephosphoramide (JP-A-61-208,758), trialkylphosphine (JP-A-62-80,976),
Morpholine (JP-A-62-80,977), aryl compounds having a carbonyl group (JP-A-62-86,67)
3), hexamethylphosphoric triamide and 4-alkylmorpholine (JP 62-217,575), bicyclic tertiary amine (JP 62-217,578), oil (JP 62 -287,580), a quaternary phosphonium salt (JP-A-63-121268), a tertiary sulfonium salt (JP-A-63-121269), and the like.

<Noncombustible high temperature resistant additive> Further, a halogen-containing solvent such as carbon tetrachloride or ethylene trifluoride chloride can be contained in the electrolytic solution in order to make the electrolytic solution nonflammable. (JP-A-48-36632) Further, carbon dioxide may be included in the electrolytic solution in order to make it suitable for high temperature storage. (JP-A-59-134,567) Further, the mixture of the positive electrode and the negative electrode may contain an electrolytic solution or an electrolyte. For example, a method is known in which the ion conductive polymer, nitromethane (JP-A-48-36,633), and an electrolytic solution (JP-A-57-124,870) are included.

<Surface Modification of Positive Electrode> Further, the surface of the positive electrode active material can be modified. For example, the surface of a metal oxide is treated with an esterifying agent (Japanese Patent Application Laid-Open No. 55-163,77).
9) or treatment with a chelating agent (JP-A-55-16)
3,780), conductive polymers (JP-A-58-163,1).
88, No. 59-14, 274), polyethylene oxide, etc. (JP-A-60-97, 561). Also, the surface of the negative electrode active material can be modified. For example, an ion conductive polymer or a polyacetylene layer may be provided (JP-A-58-111,276) or LiCl (JP-A-58-142,771).

<Collector> As the collector of the electrode active material,
A metal plate or metal foil having a low electric resistance is preferred. For example, for the positive electrode, in addition to stainless steel, nickel, aluminum, titanium, tungsten, gold, platinum, calcined carbon, etc., as a material, a material obtained by treating the surface of aluminum or stainless steel with carbon, nickel, titanium or silver is used. Used. Duplex stainless steel is effective for corrosion. In the case of coin and button batteries, nickel plating is performed on the outside of the battery. Treatment methods include wet plating, dry plating, CVD,
PVD, cladding by pressure bonding, coating, etc. are available.

For the negative electrode, as materials, stainless steel, nickel, copper, titanium, aluminum, tungsten, gold,
In addition to platinum and calcined carbon, copper or stainless steel whose surface is treated with carbon, nickel, titanium or silver, or an Al—Cd alloy is used. Examples of the treatment method include wet plating, dry plating, CVD, PVD, cladding by pressure bonding, coating and the like.

Although the surface of these materials may be oxidized, benzotriazole, triazine thiol, alkyl thiol, fluorine-based water-generating agent, silicon-based water-generating agent or the like may be used for rust-preventing treatment. As the shape, in addition to the foil, a coin button battery can, a film, a sheet, a net, a punched product, a lath body, a porous body, a foamed body, a molded body of fibers, and the like are used. The thickness is not particularly limited. In the case of a coin button battery can, in order to mount it on a substrate, the terminal may be attached by resistance welding, laser welding, or the like. The material of the terminal includes stainless steel, stainless-nickel clad material, stainless steel plated with nickel or gold, and the like, and is not particularly limited as long as it is a metal.

<Conductive Adhesive> It is also possible to fix the electrode active material and the current collector with a conductive adhesive. As the conductive adhesive, a resin obtained by adding powder or fibers of carbon or metal to a resin dissolved in a solvent, a solution obtained by dissolving a conductive polymer, or the like is used. In the case of a pellet-shaped electrode, it is applied between the current collector and the electrode pellet to fix the electrode. The conductive adhesive in this case often contains a thermosetting resin. In the case of an electrode in the case of a sheet, it is used for the purpose of electrically connecting the current collector and the electrode rather than physically adhering them.

<Gasket> When used as a coin or button battery, polypropylene, polyethylene, polyamide resin and various engineering plastics are used as the gasket. Usually, polypropylene is generally used, but a material such as engineering plastic having a high heat resistant temperature may be used in order to cope with the reflow temperature when the battery is mounted on the substrate.

<Sealant> In the case of coin or button battery, a sealant of one kind or a mixture of asphalt pitch, butyl rubber, fluorinated oil, chlorosulfonated polyethylene, epoxy resin or the like is used between the gasket and the positive and negative electrode cans. . When the sealant is transparent, it is also colored to clarify the presence or absence of application. Examples of the method for applying the sealing agent include injecting the sealing agent into the gasket, applying it to the positive and negative electrode cans, and dipping the gasket into the sealing agent solution.

<Battery Shape> The shape of the battery can be any of coins, buttons, sheets, cylinders, corners and the like. When the shape of the battery is a coin or a button, the mixture of the positive electrode active material and the negative electrode active material is used by being compressed into a pellet shape. Further, in the case of a thin coin or button, a sheet-shaped electrode may be punched and used. The thickness and diameter of the pellet are determined by the size of the battery.

The shape of the battery is a sheet, a cylinder,
In the corner, the mixture of the positive electrode active material and the negative electrode active material is mainly used after being coated, dried and compressed on the current collector. The coat thickness, length and width are determined by the size of the battery, but the coat thickness is in the compressed state after drying,
1 to 2000 μm is particularly preferable. As a pellet or sheet pressing method, a generally adopted method can be used, but a die pressing method or a calendar pressing method is particularly preferable. The pressing pressure is not particularly limited, but is 0.2 to 3
t / cm ² is preferred. The press speed of the calendar press method is preferably 0.1 to 50 m / min. The pressing temperature is preferably room temperature to 200 ° C.

<Battery Application> The application of the non-aqueous secondary battery of the present invention is not particularly limited. For example, when it is mounted on an electronic device, a color notebook computer, a black and white notebook computer, a pen input computer, a pocket (palmtop). ) PC, notebook word processor, pocket word processor,
Ebook player, mobile phone, cordless phone handset, pager, handy terminal, mobile fax, mobile copy, mobile printer, headphone stereo, video movie, LCD TV, handy cleaner, portable CD, mini disk, electric shaver,
Electronic translator, car phone, transceiver, power tool,
Electronic notebook, calculator, memory card, tape recorder,
Examples include radios, backup power supplies, and memory cards. Other consumer products include automobiles, electric vehicles, motors, lighting equipment, toys, game machines, road conditioners, irons, watches, strobes, cameras, medical equipment (pacemakers, hearing aids, shoulder massagers, etc.) and the like. Furthermore, it can be used for various military purposes and for space. It can also be combined with a solar cell.

The secondary battery using the electrode of the present invention is light in weight, has a high capacity, and has a high energy density.
It is widely applicable to portable small electronic devices such as mobile phones. The application of the non-aqueous electrolyte secondary battery of the present invention is not particularly limited, but is, for example, a backup power source for mobile phones, pagers and the like. A power supply for a wristwatch that has a power generation function. Hereinafter, the present invention will be described in more detail with reference to Examples.

<Drying of Parts> The battery of the present invention is preferably assembled in a dehumidifying atmosphere or an inert gas atmosphere. It is also preferable that the parts to be assembled are also dried in advance. As a method of drying or dehydrating the pellets, sheets and other parts, a generally adopted method can be used. In particular, it is preferable to use hot air, vacuum, infrared rays, far infrared rays, electron beams, and low humidity air alone or in combination. The temperature is preferably in the range of 80 to 350 ° C, and particularly preferably in the range of 100 to 250 ° C. The water content of the whole battery is preferably 2000 ppm or less, and each of the positive electrode mixture, the negative electrode mixture and the electrolyte is preferably 50 ppm or less from the viewpoint of cycleability.

[0061]

EXAMPLE In this example, a lithium-containing manganese oxide was used as the positive electrode active material as the positive electrode active material, and a lithium-containing silicon oxide was used as the negative electrode active material. The positive electrode, the negative electrode, and the electrolytic solution produced as described below were used. The battery had an outer diameter of 6.8 mm and a thickness of 2.1 mm. A cross-sectional view of the battery is shown in FIG.

The positive electrode was manufactured as follows. Commercial L
Graphite as a conductive agent and polyacrylic acid as a binder were mixed in a powder of i0.36MnO2.43 (containing P) at a weight ratio of 88.5: 9: 2.5 to prepare a positive electrode mixture, Next, the positive electrode mixture was pressure-molded at ² ton / cm ² into pellets having a diameter of 4.05 mm. After that, the positive electrode pellets 5 thus obtained are bonded and integrated with the positive electrode case 7 using the electrode current collector 6 made of a conductive resin adhesive containing carbon, and dried under reduced pressure at 150 ° C. for 8 hours. did.

The negative electrode was manufactured as follows. Use commercially available silicon or silicon oxide SiO with an automatic mortar
What was pulverized and sized to a size of less than or equal to μm was used as the negative electrode active material. Graphite as a conductive agent and polyacrylic acid as a binder were added to the active material in a weight ratio of 70.5: 2, respectively.
The mixture was mixed at a ratio of 1.5: 7 to obtain a negative electrode mixture, and this mixture was pressure-molded at ² ton / cm ² into a pellet having a diameter of 4.05 mm to obtain a negative electrode pellet 3. After that, the negative electrode pellet 3 thus obtained is adhered to the negative electrode case 1 by using the electrode current collector 2 made of a conductive resin adhesive containing carbon as a conductive filler and integrated, and then at 150 ° C. It was dried under reduced pressure for an hour. Further, a punched lithium foil 10 having a diameter of 4 mm was press-bonded onto the pellet to obtain a lithium-negative electrode pellet laminated electrode.

The separator is made of 4 glass fiber non-woven fabric with a diameter of 4
It was punched out to mm and used as a separator. This separator is arranged between the positive electrode and the negative electrode. As the electrolytic solution 9, a solution in which 1 mol / l of LiClO ₄ was dissolved in a mixed solvent of ethylene carbonate and diethyl carbonate in a volume ratio of 1: 2 was used. Discharge characteristics of the battery thus manufactured under the conditions of a constant current of 25 μA, a discharge (D) end voltage of 2.0 V, and a charge (C) end voltage of 3.3 V for 24 hours. Is shown in the diagram of FIG.

Similarly, the discharge characteristics of the battery using the conventional separator are shown in FIG. Regarding the battery of the present invention and the conventional battery, in the long-term cycle performance, the battery of the present invention repeats a stable cycle and has a small decrease in capacity, but the conventional battery has a gradual decrease in capacity, which is a significant difference. I understand. Especially, when the number of cycles exceeds 100, the difference becomes large.

[0066]

As described above in detail, the present invention comprises powdered silicon or silicon alloy, electronically conductive powdered carbon and a resin binder as a negative electrode active material of a non-aqueous electrolyte secondary battery. Since a negative electrode, a positive electrode using a metal oxide containing a transition metal as a constituent element as an active material, and glass fiber as a separator are used, an excellent non-aqueous electrolyte secondary battery can be provided.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an example of a battery structure used for performance evaluation of the present invention.

FIG. 2 is an explanatory diagram showing cycle characteristics of a battery according to the present invention and a conventional battery.

[Explanation of symbols]

1 Negative electrode case 2-electrode current collector 3 Negative electrode pellet 4 separator 5 Positive electrode pellet 6 electrode collector 7 Positive case 8 gasket 9 Electrolyte 10 lithium foil

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification symbol FI H01M 4/58 H01M 4/58 (72) Inventor Kensuke Tahara 1-8 Nakase, Mihama-ku, Chiba-shi, Chiba Seiko Electronic Industry Co., Ltd. (72) Inventor Tsugio Sakai 1-8 Nakase 1-8 Nakase, Mihama-ku, Chiba, Chiba Prefecture (56) References JP-A-8-130011 (JP, A) JP-A-8-31429 (JP, A) JP-A-7-201318 (JP, A) JP-A-8-213022 (JP, A) JP-A-6-325765 (JP, A) JP-A-9-245771 (JP, A) JP-A-10 -223220 (JP, A) JP-A-7-57780 (JP, A) JP-A-9-289011 (JP, A) JP-A-6-187990 (JP, A) (58) Fields investigated (Int.Cl) . ^7, DB name) H01M 10/40 H01M 2/16 H01M 4/02 H01M 4/04 H01M 4/48 H01M 4/58

Claims (4)

(57) [Claims] 1. A negative electrode comprising a lithium-containing silicon oxide or silicate, electron conductive powdery carbon and a resin binder, and a metal oxide containing a transition metal as a constituent element as an active material. And a separator provided between the positive electrode and the negative electrode, and the separator is made of glass fiber and has a basis weight of 60 to 80 g /
m ² , thickness 0.10 to 0.30 mm, air permeability 10 to 25
sec heating loss is 5 to 15%, 100 to 250 ℃
A non-aqueous electrolyte secondary battery, which is used after being dried within a range . 2. The composition formula LixSiOy as the negative electrode active material.
(However, x ≧ 0, 2>y> 0), which is reduced by an electrochemical reaction with lithium or a substance containing lithium, and the non-aqueous electrolyte according to claim 1. Secondary battery. 3. The oxide of silicon depending on an electrochemical reaction with lithium or a substance containing lithium in the battery after the battery is assembled, or inside or outside the battery during a battery manufacturing process. Alternatively, the non-aqueous electrolyte secondary battery according to claim 1, which is an oxide or silicate of silicon containing lithium obtained by occluding lithium in a silicate. 4. The lithium-containing manganese oxide LixMnOy (2 <y <3) is used as the positive electrode, and the maximum amount of lithium entering the positive electrode during charge / discharge is in the range of 0.2 <x <0.8. The non-aqueous electrolyte secondary battery according to claim 1, wherein the center is 3.5 to 0.8V.